Henry m



UNITED STATES y PATENT OFFICE.

HENRY M. RITTER, OF COVINGTON, KENTUCKY.

SPECIFICATION formingpart of Letters Patent No. 243,794, dated Julyl5, 1881. Application filed October 5, 11880. (N o model.)

To all whom @t may concern Be it known that I, HENRY M. RITTER, of Covington, Kenton county, Kentucky, have invented certain new and useful Improvements in Piano-Stools,o'f which the following is a specification.

The object of my invention is to afford a more stable support for those piano-stools, otlicechairs, and similar articles of furniture which are adapted to be adjusted vertically by means of a screw traversing a nut applied to the leg or stand of such devices. As ordinarily constructed such screws and nuts soon become worn by constant use, and the result is that the chair is rendered unsteady and has a disagreeable rocking motion, which lateral sway is especially annoying with piano-stools, because it prevents the performer havin g complete control of the instrument. To overcome these objections I dispense with the ordinary nut and apply to the upperend of the leg or other support ofthe stool or chair a metallic cap having a smooth or unthreaded bore that is traversed by the adjusting-screw. Housed within this cap is a loose segmental nut bearing against an inclined face of said cap in such a manner as to be wedged against the screw by the weight of the occupant of the stool or other seat, said nut or threaded block being incapable of revolving within its housing. As a result of this arrangement the screw is so tightly griped between the smooth bore of the cap and said segmental nut as to be maintained rigidly in its proper vertical position, no matter how much the screw and nut may wear. This preferred form of my invention may be modified, as hereinafter described.

In the annexed drawings, Figure lis an elevation of a chair or stool support embodying my improvements, the nut and its accessories being shown in section. Fig. 2 is a horizontal section of the screw, taken immediately above the cap. Fig. 3 is an axial section of the cap and segmental nut detached from each other, the lower portion of said nut being shown in elevation. Fig. 4 is a plan of a sectional nut.

Fig. 5 is an axial section of the same. Figs. 6, 7, and 8 represent other modifications of the invention. Y

Referring to Fig. l, A represents a leg or other support for a stool or chair or any other vertically-adjustable seat'or article of furniture, which leg may rest on a broad base, B, as shown, or it may be provided with feet, like all ordinary piano-stools. Securely fastened to the upper end of this supporting-member A is a metallic cap, C, having a smooth axial bore, D, which is about semicircular in transverse section and terminates with two vertical shoulders or ledges, E E', as seen in Fig. 2. Extending from these shoulders are two perpendicular and parallel Walls, F F', joined'to an incline, G, that slopes at any suitable angle. Adapted to iit in the cavity formed by these shoulders, walls, and incline is a segmental nut or slidin g non-rotatable block, H, threaded internally at I to receivethe screw J, which latter may be of any suitable shape and of any desired pitch, its upper end being furnished with a plate or spider, j, or other seat attachment. Said segmental nut or sliding non-rotatable block has a sloping face, K, of preferably the same pitch as the incline Gr of the cap O.

L is a lug or stump at the lower end of the nut, which projection enters a notch, N, in the bottom of the cap, so as to prevent said nut being drawn out when the screw is run up or when the stool is lifted bodily by its seat. To use this more simple form of my invention the nut H is inserted in the cavity of cap O in such a manner as to cause the lugL to engage with the notch N, after which act the screw J is run into said segmental nut and the chair is at once ready for use in the ordinary Way.

Evidently the weight of the stool has a tendency to force the non-rotatable nut down into the cavity of the cap; but this direct descent is vresisted by the incline G, which launches said nut toward lthe screw J, and consequently the latter is wedged very firmly between the smooth bore D of said cap and the female thread I. As a result of this tight-wedging action the screw is held so rigidly in the cap as to be preserved against any lateral sway, no matter how heavy may be the occupant of the stool. In fact, the heavier the person the more securelythe screw will be retained in position.

As the leading feature of my invention conssts in adapting a non-rotatable nut to be selftightening as soon as any end thrust is im- IOG posed on the screw traversing said nut, I do not propose to limit myself to any special construction so long as this feature is retained.

Figs. 4 and 5 show one form of a number of self-evident modifications of my invention, O in said illustrations being a ring provided with a converging tube, l?, within which is adapted to slide a nut composed of two sections, R R', that taper externally, so as to have a wedging action against the screw as said nuts are forced down into the tube. A rib, S, projects inwardly from the housing l? and engages with the two nuts R R', so as to prevent them rotating when the screw is turned but instead of using a pair of these internally-threaded sections three or more may be employed, and if pret'erred they can be octagonal or rectangular in transverse section', so as to be secured against rotation when the screw J is operated.

In Fig. 6 the two-part nut R Rl is represented as inserted in a pair of vertical openings, 1 r', of unequal diameters, thus showing that the sides ot' the nut and its socket need not be of the same shape. In Fig. 7 asin gle non-rotatable tubular nutis shown split longitudinally at T,

so as to cause it to hug the screw very closely when said nut is forced down into its socket.

In Fig. 8 a funnel-shaped socket, U, is shown havinga cylindrical extension, u. This funnel is adapted to receive the spherical or other enlarged head V of the nut, while said extension a is traversed by the shank o of said nut, which shank 'v is threaded internally to engage with the screw J, the slotted portion of said nut being smooth or unthreaded. Furthermore, this nut is slotted longitudinally at v to render it elastic or capable of having its upper or unthreaded portion compressed around .the screw. It is to be understood, however, that the nuts seen in Figs. 6, 7, and 8 are to be so iittcd to their respective seats or housings as to be secured against revolvingtherein, as any rotation of the devices R R or T or V would interfere with the proper action of screw J. One obvious way oflocking said nuts would ble them to grasp various objects, as such appliances are seen in chucks, nut-locks, Src., but I know of no instance where the longitudinal or end thrust of a screw has beenmade available to operate a self-ti ghtenin g nut traversed by the screw when said segmental nut or nuts are so arranged as to be incapable of revolving within their seats or bearings, as herein described.

I claim as my inventionl. The combination, with the seat and its adjusting-screw, of' the standard having an inclined bearing, a vertically movable screwthreaded piece engaging with said bearing, and means, substantially as described, for locking said piece against turning, as and for the purpose set forth.

2. The cap C, having a smooth bore, D, and incline Gr, in combination with the screw J, and a segmental block, H, having a female thread, l, and incline K, for the purpose stated.

3. The cap C, having a smooth bore, D, ineline Gr, and notch N, in combination with the screw J, and a segmental block, H, having a female thread, I, incline K, and lug L, for the purpose described.

4L. The combination of cap C, having smooth bore D, incline G, shoulders E E', and walls F F', the segmental block H, having screwthread I and incline K, and the screw J, as and for the purpose set forth.

In testimony of which invention l hereunto set my hand.

HENRY M. RITTER.

Witnesses:

JAMES H. LAYMAN, JOHN Q. PORTER. 

